EFFECT OF ORGANIC MODIFIER ON RESOLUTION OF HYDROPHOBIC COMPOUNDS BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY

Three organic modifiers, methanol, acetonitrile, and dimethylformamide, were used as organic modifiers to improve the resolution of hydrophobic compounds in micellar electrokinetic chromatography. The capacity factor decreased with increasing concentration of organic modifier. Acetonitrile and dimethylformamide were more effective modifiers to decrease the capacity factor than methanol. Maximum resolution was obtained when the capacity factor was reduced to about 2. Methanol enhanced the resolution for less hydrophobic compounds, while acetonitrile and dimethylformamide were better modifiers to improve the resolution for strongly hydrophobic compounds.